fix v1.43.0: external audit P0 — data loss, split geometry, auth, dialog zombies

L2 (silent data loss): debounce gains flush()/pending(); _reloadConfigOnly
flushes a pending write and defers while one is in flight; conflict path
forces; failed reload now toasts instead of an empty catch; teardown flushes.

G1 (split corruption): same-edge cuts carve the niche properly instead of
walking the outline twice; partition invariant (parts sum to the original)
rejects anything else; +1 unit test covering 5 niche shapes and both legacy
cut shapes.

B1 (unauthenticated content): plans and marker files move to
HouseplanContentView (/api/houseplan/content/..., requires_auth); only the
card bundle stays static; contentUrl() rewrites legacy URLs on read (no
storage migration); repairs.py accepts both prefixes; +1 unit test.

L3 (dialog zombies): all four save catch-blocks guard against a closed
dialog; the card no longer blanks when a save fails after Esc.

smokes: smoke_save_race, smoke_dialog_zombie; docs (TESTING/CHANGELOG/
ARCHITECTURE incl. the optimistic-UI note) same-commit

demo/smoke_save_race.mjs

@@ -0,0 +1,36 @@
+import { launch } from './serve.mjs';
+const { page, browser } = await launch();
+const res = await page.evaluate(async () => {
+  const out = {};
+  const c = window.__card;
+  const sent = [];
+  // перехват WS: config/set логируем, config/get отдаёт "серверную" копию БЕЗ локальной правки
+  const server = { cfg: JSON.parse(JSON.stringify(c._serverCfg)), rev: c._cfgRev };
+  c.hass = { ...c.hass, callWS: async (msg) => {
+    if (msg.type === 'houseplan/config/set') {
+      sent.push(JSON.parse(JSON.stringify(msg.config)));
+      server.cfg = JSON.parse(JSON.stringify(msg.config));
+      server.rev = (msg.expected_rev ?? server.rev) + 1;
+      return { rev: server.rev };
+    }
+    if (msg.type === 'houseplan/config/get') return { config: JSON.parse(JSON.stringify(server.cfg)), rev: server.rev };
+    return {};
+  } };
+  await c.updateComplete;
+  // локальная правка (как разметка комнаты) + дебаунс
+  const sp = c._curSpaceCfg;
+  sp.rooms.push({ id: 'race_room', name: 'RACE', area: null, poly: [[0.8, 0.8], [0.9, 0.8], [0.9, 0.9], [0.8, 0.9]] });
+  c._saveConfig();
+  out.pending = c._saveConfig.pending();
+  // через 100 мс приходит событие о чужой ревизии — раньше это стирало правку
+  c._cfgRev = server.rev; // симулируем: наша ревизия отстала
+  await c._reloadConfigOnly();
+  await new Promise((r) => setTimeout(r, 900));
+  // правка обязана уцелеть и уйти на сервер
+  out.editSent = sent.some((cf) => cf.spaces.some((s) => s.rooms?.some((r) => r.id === 'race_room')));
+  out.editInMemory = c._serverCfg.spaces.some((s) => s.rooms?.some((r) => r.id === 'race_room'));
+  out.serverHasIt = server.cfg.spaces.some((s) => s.rooms?.some((r) => r.id === 'race_room'));
+  return out;
+});
+console.log(JSON.stringify(res, null, 1));
+await browser.close();